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Calithera Biosciences and Antengene Enter Worldwide License Agreement for Development & Commercialization of CB-708


--CB-708 is an oral small molecule inhibitor of CD73 in preclinical development for oncology
--Antengene is granted exclusive rights to develop and commercialize asset discovered and initially developed by Calithera

SOUTH SAN FRANCISCO, Calif. and SHANGHAI, China, May 17, 2021 (GLOBE NEWSWIRE) -- Calithera Biosciences, Inc. (Nasdaq: CALA), a clinical-stage biotechnology company focused on discovering and developing novel small molecule drugs for the treatment of cancer and other life-threatening diseases, and Antengene Corporation, Ltd. (SEHK: 6996.HK), a leading clinical-stage R&D driven biopharmaceutical company focused on innovative medicines for oncology and other life-threatening diseases, today announced an exclusive, worldwide license agreement for the development and commercialization of CB-708, Calithera’s small molecule inhibitor of CD73.

“This agreement validates the capabilities of our drug discovery engine and represents a significant milestone for our CD73 program,” said Susan Molineaux, PhD, president and chief executive officer of Calithera. “Antengene brings significant enthusiasm and proven global capabilities to the development and future commercialization of CB-708, a potential best-in-class oral small molecule CD73 inhibitor. This licensing agreement enables the continued advancement of this promising program, while allowing Calithera to focus our resources on our more advanced clinical programs evaluating telaglenastat in non-small cell lung cancer and CB-280 in cystic fibrosis.”

CB-708 is a highly potent, selective, orally-bioavailable small molecule inhibitor of CD73. Preclinical data presented at the 2019 American Association for Cancer Research (AACR) Annual Meeting and the 2019 Society for Immunotherapy of Cancer (SITC) Annual Meeting demonstrated that CB-708 has immune-mediated, single agent activity in syngeneic mouse tumor models. In preclinical studies, CB-708 was well-tolerated and showed enhanced anti-tumor activity when combined with either an anti-PD-L1 immunotherapy or with chemotherapeutic agents, such as oxaliplatin or doxorubicin. CB-708 has completed GLP toxicology studies and is poised to advance into clinical development.

“We are excited to continue the advancement of CB-708 through our deep experience in global clinical development and extensive track record in commercialization in major markets around the world,” said Dr. Jay Mei, Founder and Chief Executive Officer of Antengene. “CB-708 is a highly differentiated oral small molecule CD73 inhibitor with best-in-class potential.  Antengene will continue to complete the GMP manufacturing of CB-708 and advance it into clinical trials for the treatment of multiple cancers including solid tumors and hematologic malignancies. This agreement brings a great addition to our synergistic portfolio of 12 assets with combinatory potential, is a testament to our abilities in accelerating global development, and represents another step in realizing our mission of treating patients beyond borders.”

Under the terms of the license agreement, Calithera will receive an upfront payment and potential development, regulatory and sales milestones of up to $255.0 million. Additionally, Calithera is eligible to receive tiered royalties on sales of the licensed product up to low double-digits. Antengene Investment Ltd, a wholly owned subsidiary of Antengene Corporation, will receive exclusive, worldwide rights to develop and commercialize CB-708.

About Calithera

Calithera Biosciences is a clinical-stage biopharmaceutical company pioneering the discovery and development of targeted therapies that disrupt cellular metabolic pathways to preferentially starve tumor cells and enhance immune-cell activity. Driven by a commitment to rigorous science and a passion for improving the lives of people impacted by cancer and other life-threatening diseases, Calithera is advancing a pipeline of first-in-clinic, oral therapeutics to meaningfully expand treatment options available to patients. Calithera is headquartered in South San Francisco, California. For more information about Calithera, please visit

About Antengene

Antengene Corporation Limited (“Antengene”, SEHK: 6996.HK) is a leading clinical-stage R&D driven biopharmaceutical company focused on innovative medicines for oncology and other life-threatening diseases. Antengene aims to provide the most advanced anti-cancer drugs to patients in the Asia Pacific Region and around the world. Since its establishment in 2017, Antengene has built a broad and expanding pipeline of clinical and pre-clinical stage assets through partnerships as well as in-house drug discovery, and obtained 15 investigational new drug (IND) approvals and submitted 5 new drug applications (NDA) in multiple markets in Asia Pacific. Antengene’s vision is to “Treat Patients Beyond Borders”. Antengene is focused on and committed to addressing significant unmet medical needs by discovering, developing and commercializing first-in-class/best-in-class therapeutics. For more information, please visit:

Forward Looking Statements

Statements contained in this press release regarding matters that are not historical facts are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "may," "will," "expect," "anticipate," "estimate," "intend," "poised" and similar expressions (as well as other words or expressions referencing future events, conditions, or circumstances) are intended to identify forward-looking statements. These statements include those related to the safety, tolerability and efficacy of CB-708 and Calithera’s other product candidates, Antengene’s ability to continue the development and future commercialization of CB-708, the receipt by Calithera of future development, regulatory and sales milestones, as well as tiered royalties on sales of CB-708 if successfully commercialized, the overall advancement of Calithera’s product candidates in clinical trials and intent to focus our resources on Calithera’s more advanced clinical programs evaluating telaglenastat in non-small cell lung cancer and CB-280 in cystic fibrosis, and the unmet need in the treatment of patients with advanced disease. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. CB-708, as well as the other product candidates that Calithera develops, may not progress through clinical development or receive required regulatory approvals within expected timelines or at all. In addition, clinical trials may not confirm any safety, potency or other product characteristics described or assumed in this press release. Such product candidates may not be beneficial to patients or successfully commercialized. The failure to meet expectations with respect to any of the foregoing matters may have a negative effect on Calithera's stock price. Additional information concerning these and other risk factors affecting Calithera's business can be found in Calithera's periodic filings with the Securities and Exchange Commission at These forward-looking statements are not guarantees of future performance and speak only as of the date hereof, and, except as required by law, Calithera disclaims any obligation to update these forward-looking statements to reflect future events or circumstances.

SOURCE: Calithera Biosciences, Incorporated


Stephanie Wong
Chief Financial Officer

Burns McClellan
Lee Roth

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Source: Calithera Biosciences, Inc.